Silane mixtures and processes for preparation thereof

Abstract

The silane mixture according to the invention can be prepared by mixing the silanes of the formula I and silanes of the formula II.

The invention claimed is: 
     
       1. A silane mixture comprising a silane of formula I
   (R 1 ) y (R 2 ) 3-y Si—R 3 —(S—R 4 ) n —S—R 5   (I)
 
 and a silane of formula II
   (R 1 ) y (R 2 ) 3-y Si—R 3 —(S—R 4 ) z —S—R 3 —Si(R 1 ) y (R 2 ) 3-y   (II)
 
 
 wherein R 1  are each independently C1-C10-alkoxy groups, phenoxy group, C4-C10-cycloalkoxy groups or alkyl polyether group —O—(R 6 —O) r —R 7    
 wherein R 6  are each independently a branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30 hydrocarbon group, r is an integer from 1 to 30 and R 7  is an unsubstituted or substituted, branched or unbranched monovalent alkyl, alkenyl, aryl or aralkyl group, 
 R 2  are each independently C6-C20-aryl groups, C1-C10-alkyl groups, C2-C20-alkenyl group, C7-C20-aralkyl group or halogen, 
 R 3  are each independently a branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30 hydrocarbon group, 
 R 4  are each independently a branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30 hydrocarbon group, 
 R 5  is a —C(═O)—R 8  group wherein R 8  is hydrogen, a C1-C20-alkyl group, a C6-C20-aryl groups, a C2-C20-alkenyl group, a C7-C20-aralkyl group, 
 and n is 1, 2 or 3, y are each independently 1, 2 or 3, z is 1, 2 or 3, 
 and the molar ratio of silane of the formula I to silane of the formula II is from 20:80 to 90:10. 
 
     
     
       2. The silane mixture according to  claim 1 , wherein n is 1 and z is 1. 
     
     
       3. A process for preparing the silane mixture according to  claim 2 , comprising:
 reacting a mercaptosilane of formula III
   (R 1 ) y (R 2 ) 3-y Si—R 3 —SH  (III)
 
 
 with a halogen compound of formula IV
   Hal-R 4 -Hal  (IV)
 
 
 wherein Hal is F, Cl, Br or I, 
 in a molar ratio of the mercaptosilane of formula (III) to the halogen compound of formula (IV) of from 34:66 to 76:24 to obtain a product; 
 and 
 reacting the product with a salt of a thiocarboxylic acid of formula (V)
   NaS—C(═O)—R 5   (V)
 
 
 or, 
 reacting the product with NaSH and then an acid chloride of formula (VI)
   Cl—C(═O)—R 5   (VI).
 
 
 
     
     
       4. The process for preparing the silane mixture according to  claim 3 , wherein the mercaptosilane of formula III is
 (EtO) 3 Si—(CH 2 ) 3 —SH, 
 the halogen compound of formula IV is 
 Cl—(CH 2 ) 6 —Cl, 
 and the thiocarboxylic acid of formula V is 
 NaS—C(═O)—CH 3 , NaS—C(═O)—C 7 H 15  or NaS—C(═O)—C 17 H 35 . 
 
     
     
       5. The process for preparing the silane mixture according to  claim 3 , wherein the mercaptosilane of formula III is
 (EtO) 3 Si—(CH 2 ) 3 —SH 
 the halogen compound of formula IV is 
 Cl—(CH 2 ) 6 —Cl, 
 and the acid chloride of formula VI is 
 Cl—C(═O)—CH 3 , Cl—C(═O)—C 7 H 15  or Cl—C(═O)—C 17 H 35 . 
 
     
     
       6. The silane mixture according to  claim 1 , wherein the silane of formula I is (EtO) 3 Si—(CH 2 ) 3 —(S—(CH 2 ) 6 ) n —S—C(═O)—R 8  and the silane of formula II is (EtO) 3 Si—(CH 2 ) 3 —S—(CH 2 ) 6 —S—(CH 2 ) 3 —Si(OEt) 3 , where n is 1. 
     
     
       7. The silane mixture according to  claim 1 , wherein the silane of formula I is (EtO) 3 Si—(CH 2 ) 3 —S—(CH 2 ) 6 —S—C(═O)—CH 3 , (EtO) 3 Si—(CH 2 ) 3 —S—(CH 2 ) 6 —S—C(═O)—C 7 H 15  or (EtO) 3 Si—(CH 2 ) 3 —S—(CH 2 ) 6 —S—C(═O)—C 17 H 35  and the silane of formula II is (EtO) 3 Si—(CH 2 ) 3 —S—(CH 2 ) 6 —S—(CH 2 ) 3 —Si(OEt) 3 . 
     
     
       8. The silane mixture according to  claim 1 , wherein the molar ratio of the silane of formula I to the silane of formula II is from 30:70 to 75:25. 
     
     
       9. A process for preparing the silane mixture according to  claim 1 , comprising:
 mixing the silane of formula I
   (R 1 ) y (R 2 ) 3-y Si—R 3 —(S—R 4 ) n —S—R 5   (I)
 
 
 with the silane of formula II
   (R 1 ) y (R 2 ) 3-y Si—R 3 —(S—R 4 ) z —S—R 3 —Si(R 1 ) y (R 2 ) 3-y   (II)
 
 
 in a molar ratio of 20:80-90:10. 
 
     
     
       10. The process for preparing the silane mixture according to  claim 9 , wherein n is 1 and z is 1. 
     
     
       11. The process for preparing the silane mixture according to  claim 10 , wherein the silane of formula I is
 (EtO) 3 Si—(CH 2 ) 3 —S—(CH 2 ) 6 —S—C(═O)—CH 3 , (EtO) 3 Si—(CH 2 ) 3 —S—(CH 2 ) 6 —S—C(═O)—C 7 H 15  or (EtO) 3 Si—(CH 2 ) 3 —S—(CH 2 ) 6 —S—C(═O)—C 17 H 35  and the silane of formula II is 
 (EtO) 3 Si—(CH 2 ) 3 —S—(CH 2 ) 6 —S—(CH 2 ) 3 —Si(OEt) 3 . 
 
     
     
       12. The process for preparing the silane mixture according to  claim 9 , wherein the molar ratio of the silane of formula I to the silane of formula II is from 30:70 to 75:25.